Flexible E-Paper on Its Way

In a step toward electronic newspapers and wearable computer screens, scientists have created an ultra-thin screen that can be bent, twisted and even rolled up and still display crisp text.

The material, only as thick as three human hairs, displays black text on a whitish-gray background with a resolution similar to that of a typical laptop computer screen. The screen is so flexible it can be rolled into a cylinder about a half-inch wide without losing its image quality.

Although it's not quite the dream of single-sheet, electronic newspapers or books that can display hundreds of pages of text, its creators said it's the first flexible computer screen of its kind.

"I think it's a major step forward. We have cleared a big obstacle in electronic paper development," said Yu Chen, a research scientist with E Ink of Cambridge, Massachusetts.

E Ink is one of several companies working to develop electronic "paper" for e-newspapers and e-books, and other possible applications -- even clothing with computer screens sewn into it. The new screen is described in Thursday's issue of the journal Nature. Aris Silzars, the past president of the San Jose, California-based Society for Information Display, said one of the technology's first applications could be something like an electronic tablet lawyers could use in place of bulky laptops. But Silzars said the best uses of the new screen, which E Ink is still developing, may not be evident. "It's very hard to predict where this thing may go," he said. Chen and his co-workers made the 3-inch-wide display screen flexible by developing a stainless steel foil topped with a thin layer of circuits that control an overlying film of electronic ink. The "ink," developed in 1997 by a Massachusetts Institute of Technology scientist, contains tiny capsules with black and white particles with opposing electrical charges floating in a clear fluid. When a negative voltage is run through circuits behind these capsules, the positive white particles move to the capsule's top. A positive current does the same to the negative black particles. The human eye blends these resulting patterns of black- or white-topped capsules into text displayed in a traditional column.

Currently, information and power is fed to the screen through a wired hookup. But Chen's team is working on a self-contained system that could receive data through a wireless connection. They also hope to boost the speed at which the screen switches to a new "page" of text, from the current quarter of a second to at least 10 times as fast, so it can display video. Another goal is making the screen display a full range of colors.

Robert Wisnieff, senior manager of IBM's Advanced Display Technology Laboratory in Yorktown Heights, New York, said E Ink's flexible screen is something many futurists believe is crucial to making electronic screens part of every day life. He envisions such lightweight, thin screens being used for a credit card that could display the available balance or recent purchases.

Another possible use is a jacket with a screen sewn into its sleeve to allow its wearer to read e-mail while on the run, check stock prices or access maps in an unfamiliar city.

-Associated Press

.